ICP PGN324 Installation instructions manual - page 27
27
Table 10—
Troubleshooting Guide–Heating
SYMPTOM
CAUSE
REMEDY
Burners will not ignite
Water in gas line
Drain. Install drip leg.
No power to furnace
Check power supply fuses, wiring or circuit
breaker.
No 20--v power supply to control circuit
Check transformer.
NOTE: Some transformers have internal
over--current protection that requires a cool--
down period to reset.
Mis--wired or loose connections
Check all wiring and wire nut connections
Misaligned spark electrodes
Check flame ignition and sense electrode
positioning.
Adjust as necessary.
No gas at main burners
1. Check gas line for air. Purge as neces-
sary. NOTE: After purging gas line of air,
wait at least 5 minutes for any gas to dissi-
pate before attempting to light unit.
2. Check gas valve.
Inadequate heating
Dirty air filter
Clean or replace filter as necessary
Gas input to furnace too low
Check gas pressure at manifold match with
that on unit nameplate
Unit undersized for application
Replace with proper unit or add additional
unit
Restricted airflow
Clean or replace filter. Remove any restric-
tion.
Limit switch cycles main burners
Check rotation of blower, temperature rise of
unit. Adjust as necessary.
Poor flame characteristics
Incomplete combustion results in: Aldehyde
odors, carbon monoxide, sooting flame, floating
flame
1. Tighten all screws around burner
compartment
2. Cracked heat exchanger. Replace.
3. Unit over--fired. Reduce input (change ori-
fices or adjust gas line or manifold pres-
sure).
4. Check burner alignment.
5. Inspect heat exchanger for blockage.
Clean as necessary.
Table 11—
Troubleshooting Guide–LED Error Codes
SYMPTOM
CAUSE
REMEDY
Hardware failure
(LED OFF)
Loss of power to control module (IGC)*.
Check 5--amp fue son IGC*, power to unit, 24--v cir-
cuit breaker, and transformer. Units without a 24--v
circuit breaker have an internal overload in the 24--v
transformer. If the overload trips, allow 10 minutes for
automatic reset.
Fan ON/OFF delay modified
(LED/FLASH)
High limit switch opens during heat exchang-
er warm--up period before fan--on delay ex-
pires. Limit switch opens within three min-
utes after blower--off delay timing in heating
mode.
Ensure unit is fired on rate; ensure temperature rise
is correct. Ensure unit’s external static pressure is
within application guidelines.
Limit switch faults
(LED 2 flashes)
High temperature limit switch is open.
Check the operation of the indoor (evaporator) fan
motor. Ensure that the supply--air temperature rise is
in accordance with the range on the unit nameplate.
Clean or replace filters.
Flame sense fault
(LED 3 flashes)
The IGC* sensed flame that should not be
present.
Reset unit. If problem persists, replace control board.
4 consecutive limit switch faults
(LED 4 flashes)
Inadequate airflow to unit.
Check the operation of the indoor (evaporator) fan
motor and that supply--air temperature rise agrees
with range on unit nameplate information.
Ignition lockout
(LED 5 flashes)
Unit unsuccessfully attempted ignition for 15
minutes.
Check ignitor and flame sensor electrode spacing,
gaps, etc. Ensure that fame sense and ignition wires
are properly terminated. Verify that unit is obtaining
proper amount of gas.
Induced--draft motor fault
(LED 6 flashes)
IGC does not sense that induced--draft mo-
tor is operating.*
Check for proper voltage. If motor is operating, check
the speed sensor plug/IGC Terminal J2 connection.
Proper connection:
PIN 1 -- White
PIN 2 -- Red
PIN 3 -- Black